Elastic-fluid turbine.



C. G. CURTIS.

ELASTIC FLUID TURBINE.

APPLIOATION FILED D2014, 1911.

1 ,07 1 ,887, Patented Sept. 2, 19-13.

2 SHEETS-*SHEBT 1.

l w s 1 Witnesses I veritor Attonuya.

C. G. CURTIS.

ELASTIC FLUID TURBINE.

APPLICATION FILED DEO.14, 1911.

1,071,887. Patganted Sept. 2, 1913.

2 SHEETS-SHEET 2.

- Altma- To all whom it may cancer-ii minus 6. comes,

Be it knownthatL- CHARLEs CURTIS, a

'crt-izenfof the Unitedlstaltes, residing int-he borough bfhhnhadan"; city, county, and

' State of-N'cw York, have invented a new and useful Elastic-Fluid Turbine, of which the following is a specification.

' The object I have in'view is the improveni'ent'of the economy of elastic fluid turbines when running tinder: low'po'w'er.

The invention is'primarily intended for 1 the use "of steam as the specific kind of elastic fluid employed,-. but-"the invention is not so 'limitedto the llSQOf steam.

considerableperiotfi of tinic at slower speeds -'Tlie'invention is particularly applicable formarme turbines, particularly for use in war vessels-which have a certain maximum speed but whi'eh iire intended to be run for or-under low 'Ppower.. The 'comparatii'ely poorjecoiio'my of u nine-steam turbines un- .der: low'powersiiire ninerciull Vessels, or in cruising conditions'mnaval or other vessels,

is due to the fact that the reduced power is generally obtained'by,throttling or other- "wise greatly reducing the steam flow through the turbine. This reduction of the J steam flow-results in reducing very greatly thepressure 'in the first stage and means an extremely large pressure-drop from the boiler pressure to that of the first stage of the turbine. \Vhere the first stage is built in the form of aui impulse type of turbine, this means an exceedingly high velocity delivered to the wheel by the nozzle, and since the velocity'o f the buckets is very low boczruse of the'rcduced speed of revolution, the efficiency of the first. stage, which does a very considerable part of the work under In some cases, the elliciency bccom's as low as fifteen per cent.

'Ihcobject of my invention, therefore, is to overcome this diliiculty and to provide means for very greatly increasing the elliciency of the early portion of the expansion range utilized in.-the turbine at low powers. The dillirnlty with the first stage of a turbine operating at'greatly reduced powers is that the. pressure-drop is much too. great to be ellicient, (in the case of some warships from 250 lbs. down to 15 lbs. absolute in one step) while the volume is much too small.

-M-rording to np' invention, I aim to re lure lhr pressurcalrop in the first or r-z UNITED STATES PATEN OFFICE.

or NEW YORK, N. Y.

ELASTIC-TLUID TURBINE.

V Specification of Le tters Patent. Patented SeptZ, 1913. Application filed December 14,1911- Serial m.- 665,604:

stages of the turbine to a point where it ran be etficiently' utilized by the slow moving "buckets, and I accomplish this by convertmg the energy of high pressure and small volume steam into energy of steam of much lower pressure, but nnichlarger volume, the energy of expansion-being transferred from the high pressure to the low pressure steam. This low pressure steam thcn converted into work in the first stage or the curly partof the turbine in a much more etficient manner, and the net result is a substant-iulfgain in the output of the entire machine.

These and further objects will more fully appear from the following specification and accompanying drawings, considered together or separately.

Figure l is a schematic View, partly in section, showing a portion of a multi-stuge turbine and a device in connectiontherewith, embodying my invention. Fig. 2 is a view similar to Fig. 1, but not in section, and showing a modification. Fig. 3 is an enlarged View in section on the line 3+ of Fig. 4, of the device shown in Fig. 2. Fig. l is a sectional 'iew on the line 4-4 of Fig. 3.

In all of the views, like parts are designated by the same reference clmriicters.

There are various ways in which the energy of high pressure and low rohime strain can be converted into energy of steam of low pressure and large volume. In Fig. l, I illustrate a rotary turbine compressor, the high pressure steam passing through a turbine in whit-h it develop power mul.this power being transferred to a compressor or reverse turbine whi -l: lakes slezun out of one part of the turbine, compresses it up t a certain point, um! d livers i=1 i(. a previous stage in the turbine. this steam passing ron linually through the turbine and through the compressor" alternately. in :1 continuous circuit. An ther wary of compressing the steam. illuslrafuui in Figs. "1. 3 and l, is by means of aileriee with an uspirulor or injector action. the high pressure steam lion 7 ing at high velocity utter ".CPHHSlUII in suit able nozzles and bringing in out-Jet with it thin streams of the low pressure Steam which are drawn along' by l'ri lionul action. the velocity of the r-=-uhzml mijiiili'o bring ronx'ertrd into pr by flowing ilmmgii proper shape-l Referring to 1* rairs' :1

iuriunc uh :1 m. h h are 0nd stage 4,. is in the form of a drum turbine 7 having complete peripheral admission;

the vthird sta e 5, is a turbine of the same type having t e steam flowing in the reverse direction by means. of passages 6. At full powers or igh speeds, the steam passes in succession throng speeds, the

stage 2-is cut out, no steam being admitted to the nozzles 3, 3, unless a small amount be utilized-to prevent the blades in-that stage from absorbing power. At these low 7 wers or cruisin s eeds the steam is.

admitted in the first instance through-the passage 7, to a high, pressure turbine 8. his turbine is so proportioned that it will .work in an eflicient manner with the small volume of steam admitted'under low powers. The cxhaust'in this --t-urbine-will go through the passage 9, into the space 10 between the first and second stages, and will pass through the succeedin stages, doing work therein; Coupled to t e shaft of the tuihine 8, is a compressor 11, which may be in the form of a stage'compression rotary compressor, or a reverse steam turbine suc as illustrated in my co-pending application A for Patent, No. 601606, filed August 4, 1896',

or No. 360058, filed March 1, 1907. This com rcssor takessteam from the discharge of t e second stage 4, through the passage 12, and after compressing it, delivers it to a assage 13, into the space 10, so that it wil ass through the stage 4, doing work therein, The large volume of low pressure steam discharged from the second stage has its pressure raised by means of the com: prcssor to' a oint where the pressure-drop between the inlet and outlet of that stage can be efliciently' utilized under conditions of bucket speed existing.

,Assuming, for example, under ordinary cruising Idonditions, at say one-tenth of the maximum power of the turbine, the first stage 2 does one-third of the work, the two other stages together do the'other two-thirds of: the work,-aud assuming. that the efliciency of the first stage which at one-tenth power is only 15%, by means of the apparatus above described, if the stage 4 is given an efliciency of say 371%, then the out M of this stage will increased two an one-half times, and the out ut of the-entire apparatus will he increase It will be understood, therefore, that if the efliciency of the first stage in operation or the early part of the turbine, can be improved to this extent by operating it with steam at quite a low pressure, giving a velocity which the buckets are adapted to utilize efficiently, but of larger the stages 2,. 4 and '5.- .At low powers, or :for cruising enlarges in cross-section, thus causin Figs. 2, 3 and 4, inplacelof the turbine 8,

and rotary compressor 11,1 employ a device 14;, working as an injector or aspirator. connection 17, and passes then through the annularpassage 18, this passage being in line with the nozzles 16. The high pressure steam in .the passage 15 will be converted into velocity through the nozzles 16, and this steam at high'velocity will draw in or inject the steam of low pressure and great bulk as passed through the stage 4.

This steam will be compressed and exhaust ed through the pipe 20 'into the'space 10 in advance of the second stage. After pass- ,pipe 15, and is ejected through the annular fexpanding nozzles 16. The low pressure lsteam from the second stage 4 passing ;through the pipe 12 of Fig. 1, enters the ,connection 17, and passes then through the ing the point where the two streams of 'st'eamcome together, the passage gradualtlly t e velocity of, the mixture to be converte into pressure; A

' In accordance with the provisions of the patent statutes, I have described the principle ofmv invention, together with the apparatus which I now consider to represent the best embodiment thereof: but I desire to have it understood that the ap aratus shown is merely illustrative and -t at the invention can be carried. out in other ways.

Having now described my invention, what I claim as new and desire to secure by Letters Patent'is:--v

1. An elastic fluid turbine having a stage of high pressure, means for admitting fluid of high pressure to such stage, a stage of lower pressure receiving the fluid dis.- charged from such high pressure stage, means converting energ' -of fluid, at low pressure and large volume, discharging from such stage of lower Jressure, such meansbeing 0 rated by flui of high pres sure and smal volume, and means for admitting such high pressure fluid to such converting means, independently of the high pressure stage. 4

2. An elastic fluid turbine having astage of high pressure, means for admitting fluid of high pressure to such stage, a stage of lower pressure receiving the fluid discharged from such hi h pressure stage, means operated by fluid at high pressure and small volume, operating uponthe'discharge of said stage of lower pressure, to compress said fluid said means being operated by fluid independently of the first stage.

3. An elastic fluid turbine having a stage of high pressure, means for admitting fluid of high pressure to such stage, a stage of lower pressure receiving the fluid dis-- charged from such high pressure stage, a fluid compressing device separate from the stage of lower pressure, said device being operated by fluid of high ressure and small volume, to compress fluid ischargd by said sta e.

f An elastic fluid turbine havin a stage of high pressure, means for admitting fluid of high pressure to such stage, a stage of lower pressure receiving the fluid discharged from such high pressure stage, a fluid co1npressing device coiirdinated with said stage of lower pressure in'such a manner that fluid flows in circuit through'said stage and compressor and is compressed by the latter, and expands in the former, said compressor being operated by fluid of high pressure and small volume.

5. An elastic fluid turbine having a sta e of high pressure, means for admittlng fluid 'of high pressure to such stage, a stage of lower pressure receiving the fluid discharged from such high pressure stage, and a fluid compressing device coiirdinated with the stage of lower pressure in such a manner that fluid of low pressure and large volume will flow in circuit through the two, means for operatively connecting fluid of high pressure and small volume with said device, whereby said device will be operated by the expansion of the high pressure .fluid, and means for discharging said fluid after expansion into the stage of lower pressure.

that fluid of low I ume will flow in circuit through the two,

6. An elastic fluid turbine, having a stage of high pressure,'means foradmitting fluid of high pressure to such stage, a stage of lower pressure receiving the fluid discharged from such high pressure stage, and a fluid compressing device, coordinated with the stage of lower pressure in sucha manner that fluid of, low pressure and'large volume will flow in circuit through the two means for operatively connecting fluid oi high pressure and small volume with said device, whereby said device will be operated by the expansion of' the high pressure fluid, and means for exhausting a portion of the discharge from said stage into a second stage of lower pressure.

7. An elastic fluid turbine having a sta e of high pressure, means for admitting flu d of high pressure to such stage, a stage of lower pressure receiving the fluid discharged from such high pressure stage, and a fluid compressing device coordinated with the stage of lower pressure in such a manner pressure and large volmeans for operatively {connecting fluid of high pressure and small volume with said device, whereby said device willbe operated ressure fluid,"

by the expansion of the high means for discharging said uid after expansion into thestage, and means for exausting a portion of the discharge from said stage into a second stage of lower pressure.

This specification signed and witnessed this 12th day of December, 1911.

CHARLES G. CURTIS. Witnesses: s JOHN L. Larson, GUSTAV A; SCHELLACK.

.Gopies of this patent may be obtained for five cents each, by addressiiig the Commissioner of Patents.

' Washington, D. 0. 

